Bumper reinforcement structure

Abstract

A bumper reinforcement structure capable of achieving a weight reduction while still securing required bending strength in a bumper reinforcement structure with closed cross-section structure configured by joining together an inside member and an outside member. A bumper reinforcement is formed with two closed cross-sections configured by joining together three top-to-bottom flanges of an inner panel to three top-to-bottom flanges of an outer panel. The flanges of the inner panel are disposed in the same front-rear direction position as that of the wall portions that configure the closed cross-sections.

The invention claimed is: 
     
       1. A bumper reinforcement structure comprising:
 an inside member disposed along a vehicle width direction at a vehicle front-rear direction end portion of a vehicle and supported from a vehicle front-rear direction central side by a framework member, the inside member being formed with plural indented portions provided between three or more joint sections separated from each other in the vehicle top-bottom direction and opening towards the opposite side to the framework member side; 
 an outside member being formed with three or more joint sections and a wall portion that configures a closed cross-section in combination with the indented portion, the three or more joint sections respectively joined to each of the inside member joint sections, and the three or more joint sections and at least a portion including both vehicle top-bottom direction end portions of the wall portion are disposed as each other on a same straight line in a cross-section orthogonal to a length direction of the closed cross-section; and 
 a bead with length direction running along the vehicle width direction being formed to the wall portion configuring the outside member; 
 wherein centroid of the bumper reinforcement is positioned at a wall portion side from an end at a projecting side of the bead formed from the wall portion, 
 non-continuous portions are provided at least at portions between the adjacent joint sections in the vehicle width direction, 
 the non-continuous portions are a plurality of cutout portions formed in the vehicle width direction at the top end portion and the bottom end portion of the outside member, and 
 the closed cross-section is in communication with external portions through the cut out portions. 
 
     
     
       2. The bumper reinforcement structure of  claim 1  wherein:
 the inside member is supported by the framework member at both the vehicle width direction end sides; and 
 the bead is formed between locations of support by the framework member. 
 
     
     
       3. The bumper reinforcement structure of  claim 1  wherein:
 non-continuous portions are provided at at least portions between the adjacent joint sections in the vehicle width direction at an inside member side or an outside member side of the joint sections. 
 
     
     
       4. The bumper reinforcement structure of  claim 1  wherein the vehicle width direction positions of the non-continuous portions are offset between the joint sections positioned at the vehicle top-bottom direction top end and the joint sections positioned at the vehicle top-bottom direction bottom end. 
     
     
       5. The bumper reinforcement structure of  claim 1  wherein the non-continuous portions are formed at the joint section of the outside member so as to communicate the closed cross-sections formed by the inside member and the outside member with a portion external to the closed cross-sections. 
     
     
       6. The bumper reinforcement structure of  claim 1  wherein:
 the outer panel is formed with an upper panel and a lower panel, and the upper panel and the lower panel are overlapped at a central portion in the vehicle top-bottom direction. 
 
     
     
       7. The bumper reinforcement structure of  claim 1  wherein:
 the outer panel is formed with an upper panel and a lower panel, and a thickness of the upper panel and a thickness of the lower panel are different from each other.